1. Technical Field
The present application relates to a method for making semiconducting single walled carbon nanotubes.
2. Discussion of Related Art
Single walled carbon nanotubes (SWCNTs) may be metallic or semiconducting, and may have varying diameters and lengths. Applications using SWCNTs may be improved if SWCNTs of uniform conductivity, such as all semiconducting SWCNTs or all metallic SWCNTs, are provided. Accordingly, a method for making semiconducting SWCNTs is desired.
A method for making semiconducting SWCNTs involves destruction of metallic SWCNTs by electric current (See, Collin P. et al., Science, 2001, 292, 706). A principle of this method is that semiconducting SWCNTs can be turn “off” by applying a gate voltage. It is possible to burn out metallic SWCNTs by application of a high source-drain voltage in the presence of oxygen. However, when a current flows through the metallic SWCNTs, Joule heat generated by the metallic SWCNTs might inadvertently burn out the adjacent semiconducting SWCNTs.
What is needed, therefore, is to provide a method for making semiconducting SWCNTs that can overcome the above-described shortcomings